1. Field of the Invention
The present invention relates to a telephone apparatus having a calling card support function, which enables telephone communications using card information on a calling card. The present invention further relates to an in-vehicle handsfree apparatus.
2. Description of Related Art
There is known a telephone apparatus having a calling card support function, which enables telephone communications using card information on a calling card. According to such telephone apparatus, a user can input card information (e.g., access number and PIN code typically appearing on a face of a calling card,) to the telephone apparatus thereby to record the card information in the telephone apparatus. Then, a user can directly input a telephone number of a call destination or reference phone book date to select the phone number of the call destination. In response to the input of the call destination, the telephone apparatus transmits the access number to a center (i.e., a center for providing telephone service using card information on a calling card) as a dialed phone number and transmits a PIN code to the center. Provided that authentification of the PIN code is successful, the telephone apparatus and the call destination are connected to each other via a telephone communication link, and the telephone communications becomes possible. For such telephone apparatus, refer to JP-H5-22477A, JP-H11-239232A corresponding to U.S. Pat. No. 6,009,156, and JP-H5-122408A.
The inventor of the present application has considered that a typical telephone apparatus involves the following difficulty. In typical calling-card-based telephone communications, a communication network side (e.g., a telephone service provider) allows a user to perform the telephone communications using a calling card, provided that the balance on the calling card is larger than zero, in other words, the calling card has a credit balance. When the balance on the calling card reaches zero (the calling card becomes zero balance), the already-established communication link with the communication counterpart is forcibly disconnected by the telephone service provider. When the already-established communication link with the communication counterpart is forcibly disconnected, a user needs to input the card information on another calling card having a credit balance to the telephone apparatus and needs to redial in order to restart the telephone communication with the same communication counterpart. In the above, the operation of inputting of card information of another calling card to a telephone apparatus and then redialing is disadvantageously cumbersome for a user. It should be noted that no measures against this difficulty is suggested and taught in the above-described references: JP-H5-22477A JP-H11-239232A corresponding to U.S. Pat. No. 6,009,156, and JP-H5-122408A.